The remote key fob won't open the doors by pressing any keys on it. I can, however, lock and unlock all of the doors by turning the integrated key inside the driver's door. So the central locking system works fine. It's just the remote that doesn't work.
The key fob seems to be working - accordingly to some specialist who tested it with his gauge. The battery replacement also didn't help. I've disassembled the diversity module and it looks as it was new. It does not look as if water got into it or anything - it was just dusty.
The radio reception is flawless. So I have idea where to go next. Is there a way to test the diversity module somehow? I don't want to blindly replace it and face the same issue.
The BMW in subject is E91 2006, 320d.